Electroacupuncture at Feishu (BL13) and Zusanli (ST36) down-regulates the expression of orexins and their receptors in rats with chronic obstructive pulmonary disease

Inflammation and lung function decline are the main pathophysiological features of chronic obstructive pulmonary disease (COPD). Acupuncture can improve lung function in patients with COPD, but the underlying mechanisms are not well understood. Orexins (OXs), which are found in peripheral plasma, ar...

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Published in结合医学学报:英文版 Vol. 12; no. 5; pp. 417 - 424
Main Author Xin-fang Zhang Ji Zhu Wen-ye Geng Shu-jun Zhao Chuan-wei Jiang Sheng-rong Cai Miao Cheng Chuan-yun Zhou Zi-bing Liu
Format Journal Article
LanguageEnglish
Published 2014
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Summary:Inflammation and lung function decline are the main pathophysiological features of chronic obstructive pulmonary disease (COPD). Acupuncture can improve lung function in patients with COPD, but the underlying mechanisms are not well understood. Orexins (OXs), which are found in peripheral plasma, are neuropeptides that regulate respiration and their levels are related to COPD. Therefore, we hypothesized that acupuncture might alter OXs, reduce lung inflammation and improve lung function in COPD. METHODS: COPD was induced in rats by exposure to cigarette smoke for 8 weeks and injecting with lipopolysaccharide twice. Electroacupuncture (EA) was performed at Feishu (BL13) and Zusanli (ST36) for 30 min/d for 2 weeks. Rat lung function and morphology were assessed after EA. The levels of tumor necrosis factor-α (TNF-a) and intedeukin-1β (IL-16) in bronchoalveolar lavage fluid (BALF) and orexin A and B levels in the lung tissue were detected by enzyme-linked immunosorbent assay. OX receptor mRNA levels and immunopositive cells were assessed with real-time polymerase chain reaction and immunohistochemical methods, respectively. The relationships among lung function, cell factors, and OX levels were analyzed by Pearson correlation analyses. RESULTS: Compared with the control group, lung function was significantly decreased in the rats with COPD (P〈0.05). There were obvious increases in TNF-α and IL-1β levels in BALF (P〈0.05 and P〈0.01, respectively), orexin A level in lung tissue (P〈0.01; but not orexin B) and mRNA expressions of OX 1 type receptor (OXR1) and OX 2 type receptor (OXR2) in lung tissue (P〈0.05 and P〈0.01, respectively); the integrative optical densities (IODs) of both receptors were greater in the COPD group (P〈0.05). For rats with COPD subjected to EA, lung function was improved (P〈0.05). There were notable decreases in TNF-a and IL-1β levels (P〈0.05 and 〈0.01, respectively) in BALF. Orexin A, but not orexin B, levels in lung tissue also decreased (P〈0.01), as did mRNA expression of OXlR and OX2R in lung tissue (P〈0.05 and P〈0.01, respectively). Receptor IODs were also reduced after EA treatment (P〈0.05). Furthermore, orexin A levels and ratio of forced expiratory volume in 0.3 s to forced vital capacity were strongly negatively correlated (P〈0.01), and orexin A was positively correlated with TNF-α and IL-1β (P〈0.001 and P〈0.05, respectively).CONCLUSION: EA at Zusanli and Feishu improved lung function of rats with COPD and had an anti-inflammatory effect, which may be related to down-regulation of OXA and its receptors.
Bibliography:pulmonary disease,-chronic obstructive; electroacupuncture; Point BL13 (Feishu);Point ST36 (Zusanli); orexin; anti-inflammation; rats
Inflammation and lung function decline are the main pathophysiological features of chronic obstructive pulmonary disease (COPD). Acupuncture can improve lung function in patients with COPD, but the underlying mechanisms are not well understood. Orexins (OXs), which are found in peripheral plasma, are neuropeptides that regulate respiration and their levels are related to COPD. Therefore, we hypothesized that acupuncture might alter OXs, reduce lung inflammation and improve lung function in COPD. METHODS: COPD was induced in rats by exposure to cigarette smoke for 8 weeks and injecting with lipopolysaccharide twice. Electroacupuncture (EA) was performed at Feishu (BL13) and Zusanli (ST36) for 30 min/d for 2 weeks. Rat lung function and morphology were assessed after EA. The levels of tumor necrosis factor-α (TNF-a) and intedeukin-1β (IL-16) in bronchoalveolar lavage fluid (BALF) and orexin A and B levels in the lung tissue were detected by enzyme-linked immunosorbent assay. OX receptor mRNA levels and immunopositive cells were assessed with real-time polymerase chain reaction and immunohistochemical methods, respectively. The relationships among lung function, cell factors, and OX levels were analyzed by Pearson correlation analyses. RESULTS: Compared with the control group, lung function was significantly decreased in the rats with COPD (P〈0.05). There were obvious increases in TNF-α and IL-1β levels in BALF (P〈0.05 and P〈0.01, respectively), orexin A level in lung tissue (P〈0.01; but not orexin B) and mRNA expressions of OX 1 type receptor (OXR1) and OX 2 type receptor (OXR2) in lung tissue (P〈0.05 and P〈0.01, respectively); the integrative optical densities (IODs) of both receptors were greater in the COPD group (P〈0.05). For rats with COPD subjected to EA, lung function was improved (P〈0.05). There were notable decreases in TNF-a and IL-1β levels (P〈0.05 and 〈0.01, respectively) in BALF. Orexin A, but not orexin B, levels in lung tissue also decreased (P〈0.01), as did mRNA expression of OXlR and OX2R in lung tissue (P〈0.05 and P〈0.01, respectively). Receptor IODs were also reduced after EA treatment (P〈0.05). Furthermore, orexin A levels and ratio of forced expiratory volume in 0.3 s to forced vital capacity were strongly negatively correlated (P〈0.01), and orexin A was positively correlated with TNF-α and IL-1β (P〈0.001 and P〈0.05, respectively).CONCLUSION: EA at Zusanli and Feishu improved lung function of rats with COPD and had an anti-inflammatory effect, which may be related to down-regulation of OXA and its receptors.
31-2083/R
ISSN:2095-4964